Wireless communication systems are widely spread all over the world to provide various types of communication services such as voice or data. In general, the wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of the multiple access system include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, a single carrier frequency division multiple access (SC-FDMA) system, etc.
SC-FDMA has almost the same complexity with OFDMA, and has a lower peak-to-average power ratio (PAPR) due to a single carrier property. Since the lower PAPR is advantageous to a user equipment in terms of transmit power efficiency, the SC-FDMA is adopted in uplink transmission in 3rd generation partnership project (3GPP) long term evolution (LTE) as disclosed in the section 5 of 3GPP TS 36.211 V8.0.0 (2007-09) “Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation (Release 8)”.
Meanwhile, various uplink control signals are transmitted through an uplink control channel. Examples of the uplink control signal include an acknowledgement (ACK)/not-acknowledgement (NACK) signal for performing hybrid automatic repeat request (HARQ), a channel quality indicator (CQI) for indicating downlink channel quality, a scheduling request (SR) for requesting resource allocation for uplink transmission, etc.
When an error occurs in transmission of the uplink control signal, the wireless communication system may experience overall performance deterioration, and thus the uplink control signal needs to be transmitted with high reliability. In order to improve system performance, there is a need for a method capable of effectively transmitting the uplink control signal.